NAT: allow allocating BSC in arbitrary order

Check for existing BSC before allocating new one.
Track number of remaining BSCs on deallocation.
Explicitly use BSC number in allocation function.

4 files changed, 18 insertions, 20 deletions

diff --git a/openbsc/include/openbsc/bsc_nat.h b/openbsc/include/openbsc/bsc_nat.h
index 309adb1ba..c5fefe172 100644
--- a/openbsc/include/openbsc/bsc_nat.h
+++ b/openbsc/include/openbsc/bsc_nat.h
@@ -320,7 +320,8 @@ struct bsc_nat_ussd_con {
 };
 
 /* create and init the structures */
-struct bsc_config *bsc_config_alloc(struct bsc_nat *nat, const char *token);
+struct bsc_config *bsc_config_alloc(struct bsc_nat *nat, const char *token,
+				    unsigned int number);
 struct bsc_config *bsc_config_num(struct bsc_nat *nat, int num);
 struct bsc_config *bsc_config_by_token(struct bsc_nat *nat, const char *token, int len);
 void bsc_config_free(struct bsc_config *);
diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat_utils.c b/openbsc/src/osmo-bsc_nat/bsc_nat_utils.c
index cc7d44287..37b01e314 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_nat_utils.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_nat_utils.c
@@ -155,14 +155,15 @@ struct bsc_connection *bsc_connection_alloc(struct bsc_nat *nat)
 	return con;
 }
 
-struct bsc_config *bsc_config_alloc(struct bsc_nat *nat, const char *token)
+struct bsc_config *bsc_config_alloc(struct bsc_nat *nat, const char *token,
+				    unsigned int number)
 {
 	struct bsc_config *conf = talloc_zero(nat, struct bsc_config);
 	if (!conf)
 		return NULL;
 
 	conf->token = talloc_strdup(conf, token);
-	conf->nr = nat->num_bsc;
+	conf->nr = number;
 	conf->nat = nat;
 	conf->max_endpoints = 32;
 	conf->paging_group = PAGIN_GROUP_UNASSIGNED;
@@ -205,6 +206,8 @@ void bsc_config_free(struct bsc_config *cfg)
 	llist_del(&cfg->entry);
 	rate_ctr_group_free(cfg->stats.ctrg);
 	talloc_free(cfg);
+	cfg->nat->num_bsc--;
+	OSMO_ASSERT(cfg->nat->num_bsc >= 0)
 }
 
 static void _add_lac(void *ctx, struct llist_head *list, int _lac)
diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c b/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c
index 5af6d9743..4348d6fb8 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c
@@ -799,17 +799,11 @@ DEFUN(cfg_bsc, cfg_bsc_cmd, "bsc BSC_NR",
       "BSC configuration\n" "Identifier of the BSC\n")
 {
 	int bsc_nr = atoi(argv[0]);
-	struct bsc_config *bsc;
+	struct bsc_config *bsc = bsc_config_num(_nat, bsc_nr);
 
-	if (bsc_nr > _nat->num_bsc) {
-		vty_out(vty, "%% The next unused BSC number is %u%s",
-			_nat->num_bsc, VTY_NEWLINE);
-		return CMD_WARNING;
-	} else if (bsc_nr == _nat->num_bsc) {
-		/* allocate a new one */
-		bsc = bsc_config_alloc(_nat, "unknown");
-	} else
-		bsc = bsc_config_num(_nat, bsc_nr);
+	/* allocate a new one */
+	if (!bsc)
+		bsc = bsc_config_alloc(_nat, "unknown", bsc_nr);
 
 	if (!bsc)
 		return CMD_WARNING;
diff --git a/openbsc/tests/bsc-nat/bsc_nat_test.c b/openbsc/tests/bsc-nat/bsc_nat_test.c
index a4b313c91..a405763bc 100644
--- a/openbsc/tests/bsc-nat/bsc_nat_test.c
+++ b/openbsc/tests/bsc-nat/bsc_nat_test.c
@@ -316,7 +316,7 @@ static void test_contrack()
 	printf("Testing connection tracking.\n");
 	nat = bsc_nat_alloc();
 	con = bsc_connection_alloc(nat);
-	con->cfg = bsc_config_alloc(nat, "foo");
+	con->cfg = bsc_config_alloc(nat, "foo", 0);
 	bsc_config_add_lac(con->cfg, 23);
 	bsc_config_add_lac(con->cfg, 49);
 	bsc_config_add_lac(con->cfg, 42);
@@ -434,7 +434,7 @@ static void test_paging(void)
 
 	nat = bsc_nat_alloc();
 	con = bsc_connection_alloc(nat);
-	cfg = bsc_config_alloc(nat, "unknown");
+	cfg = bsc_config_alloc(nat, "unknown", 0);
 	con->cfg = cfg;
 	bsc_config_add_lac(cfg, 23);
 	con->authenticated = 1;
@@ -476,7 +476,7 @@ static void test_mgcp_allocations(void)
 	nat->mgcp_cfg->trunk.number_endpoints = 64;
 
 	bsc = bsc_connection_alloc(nat);
-	bsc->cfg = bsc_config_alloc(nat, "foo");
+	bsc->cfg = bsc_config_alloc(nat, "foo", 0);
 	bsc->cfg->max_endpoints = 60;
 	bsc_config_add_lac(bsc->cfg, 2323);
 	bsc->last_endpoint = 0x22;
@@ -522,7 +522,7 @@ static void test_mgcp_ass_tracking(void)
 	mgcp_endpoints_allocate(&nat->mgcp_cfg->trunk);
 
 	bsc = bsc_connection_alloc(nat);
-	bsc->cfg = bsc_config_alloc(nat, "foo");
+	bsc->cfg = bsc_config_alloc(nat, "foo", 0);
 	bsc_config_add_lac(bsc->cfg, 2323);
 	bsc->last_endpoint = 0x1e;
 	con.bsc = bsc;
@@ -874,7 +874,7 @@ static void test_cr_filter()
 
 	struct bsc_nat *nat = bsc_nat_alloc();
 	struct bsc_connection *bsc = bsc_connection_alloc(nat);
-	bsc->cfg = bsc_config_alloc(nat, "foo");
+	bsc->cfg = bsc_config_alloc(nat, "foo", 0);
 	bsc_config_add_lac(bsc->cfg, 1234);
 	bsc->cfg->acc_lst_name = "bsc";
 	nat->acc_lst_name = "nat";
@@ -953,7 +953,7 @@ static void test_dt_filter()
 	struct bsc_connection *bsc = bsc_connection_alloc(nat);
 	struct nat_sccp_connection *con = talloc_zero(0, struct nat_sccp_connection);
 
-	bsc->cfg = bsc_config_alloc(nat, "foo");
+	bsc->cfg = bsc_config_alloc(nat, "foo", 0);
 	bsc_config_add_lac(bsc->cfg, 23);
 	con->bsc = bsc;
 
@@ -1525,7 +1525,7 @@ static void test_nat_extract_lac()
 	/* initialize the testcase */
 	nat = bsc_nat_alloc();
 	bsc = bsc_connection_alloc(nat);
-	bsc->cfg = bsc_config_alloc(nat, "foo");
+	bsc->cfg = bsc_config_alloc(nat, "foo", 0);
 
 	memset(&con, 0, sizeof(con));
 	con.bsc = bsc;